The present invention relates generally to a system for data transmission across what are commonly known as telephone lines, and more particularly, to a system for authorization of financial cards transactions.
Financial cards, usually credit cards, are commonly used by purchasers in retail establishments to pay for goods purchased. The retail establishment normally verifies that the credit card is approved for such transactions by verification through a credit card approver such as a bank or credit card company. The retail establishments are usually equipped with a terminal containing a modem which is connected to a local telephone line. A portion of the credit card is normally passed through a slot in the terminal at which time identification information is collected from the card. The terminal then automatically dials a previously programmed phone number to begin the authorization process. The number called by the authorization terminal will be an answering modem and this answering modem may be connected to a packet assembler/disassembler (PAD) or other multiplexer or concentrator that may be connected through another line to a host computer. When the answering modem takes the call from the authorization terminal modem, the identification information is transmitted across the line. The host computer processes this information and transmits back to the authorization terminal whether or not the credit card has been approved for this transaction.
Even if the telephone number which the authorization terminal modem dials is a local number, the retail establishment is still charged a nominal rate for each local call. These charges incurred by the retailer can become quite significant when it is considered that several credit card authorization calls may be made each business day. Some credit card companies have opted to attempt to absorb the local call charges incurred by the retailers. In the past, this has been done by offering a 1-800 number for the retailer to call for credit call approval. In this way, the retailer is not charged for the local call, but instead the number being called is billed for the call.
Efforts were also undertaken to shorten the time for each authorization call. In this regard, the modems were provided with ground start interfaces which allowed the call coming from the retailer to be answered by the answering modem before the answering modem actually rang.
Other known systems have used channel banks and FXS channel interface cards along with a ground-start interface to translate to/from an E&M supervisory signalling format. The present invention accomplishes the intended function without employing channel bank cards or an FXS interface card. Known systems have required an associated dedicated modem and channel bank for each access tandem. This requires additional dedicated hardware to service each access tandem. However, the present invention is dynamic in that it is capable of using a single piece of hardware to connect with multiple access tandems. This hardware results in the need for fewer RS-232 interfaces than required by the known systems. This is a significant cost savings. Additionally, the known systems require an analog-to-digital conversion mechanism to convert the digitized transmission to an analog transmission in the form of voice and multi-frequency (MF) tones mixed together. In the known systems the analog signal passes through physical interfaces to an MF receiver and ultimately to the modem. The analog signal is then converted to digital form for transmission to an exchange carrier (EC) access tandem. As stated previously, the present invention does not require analog to digital conversion. The present invention is entirely digital which results in a faster processing time that translates into less usage of telephone lines and, therefore less cost per call.
The present invention represents a dramatic improvement in the state of the art of credit card authorization. The present invention takes advantage of the opportunity that credit card companies now have to become interexchange customers (IXC) through the telephone system network. The present invention takes advantage of relatively new trunk interfaces known as Feature Groups. There are currently four defined Feature Groups known as A, B, C and D. In the present invention the retailer's authorization terminal modem initiates a call through a local exchange office and from the exchange office the call is directed to an access tandem (AT) switch to gain access to long distance service. From the access tandem, the information is transferred across a Feature Group trunk to a network access system (NAS) device which demultiplexes and demodulates the signal. NAS works in conjunction with a plurality of asynchronous RS-232 interfaces and one or more micronodes which act as a packet assembler/disassembler and network processor or packet switch for accomplishing formatting, error checking, etc. NAS and the micronode(s) system are entirely digital and do not require analog to digital conversion capabilities. From the micronode(s), the transaction data is transferred through a value-added network, such as that provided by CompuServe, the applicant for the present invention. The signal may be transferred via an X0.25 protocol and is ultimately received by a host computer.
Further objects and advantages of the invention will become apparent when viewed in light of the following drawings and detailed description.